A gas shutoff device in the related art is constituted, as shown in FIG. 2, by a flow rate detection section 1 which outputs a flow rate signal ‘a’ in response to a gas flow rate passing through a gas passage; a flow rate calculation section 2 which calculates a flow rate ‘b’ upon receiving the flow rate signal ‘a’; an abnormal flow rate determination section 3 which compares the flow rate ‘b’ with a previously-retained determination value upon receiving the flow rate, and outputs a valve-closing signal ‘c’ if abnormality exists in the comparison; a valve driving section 4 which outputs a valve driving signal ‘d’ upon receiving the valve-closing signal ‘c’ from the abnormal flow rate determination section 3, a valve-opening signal from a recovery input section 8, or the valve-closing signal ‘c’ from a sensor abnormality determination section 6; a valve 5 which opens or closes the gas passage upon receiving the valve driving signal ‘d’; the sensor abnormality determination section 6 which performs an abnormality determination whether the flow rate signal ‘a’ from the flow rate detection section 1 is in accord with a predetermined abnormal condition, and outputs the valve-closing signal ‘c’ only if the abnormality exists; an accumulation section 7 which accumulates and retains the flow rate ‘b’ from the flow rate calculation section 2; and the recovery input section 8 which outputs the valve-opening signal ‘e’ upon accepting a recovery input from outside (refer to Patent Literature 1, for example).